and normal tissues. The nature and extent of such effects, however, depend on selected biological parameter (e.g., oxygen supply, cell cycle) and can be modified by chemical agents such as radiosensitizers, radioprotectors and chemotherapeutic agents. A precise control of the mode of action of the radiation is important in order to achieve the maximum effect on tumor tissue, while minimizing th...

Abstract Loganiaceae is a member of the Gentianales order and comprises about 460 species in 16 genera, being mainly distributed tropical regions world. The Brazilian Neotropical region one centers diversity for two richest genera Loganiaceae, Spigelia Strychnos, justifying floristic efforts to better understand family this region. This study aims update taxonomic knowledge state Pernambuco, No...

BACKGROUND AND AIMS Pseudopollen is a whitish, mealy material produced upon the labella of a number of orchid species as labellar hairs either become detached or fragment. Since individual hair cells are rich in protein and starch, it has long been speculated that pseudopollen functions as a reward for visiting insects. Although some 90 years have passed since Beck first described pseudopollen ...